1. Field of the Invention
The present invention relates to a camera, and more particularly to a camera having a press spring for pressing a filmstrip on a take-up spool.
2. Description Related to the Prior Art
When a film cartridge of IX240 type is loaded in a camera, a drive shaft of the camera is engaged with a spool of the film cartridge and rotated to advance a filmstrip wound around the spool in the film cartridge. The filmstrip advanced from the film cartridge passes through a film passage way disposed between a rear cover and an exposure aperture on the filmstrip, and reaches the film take-up chamber.
Inside the film take-up chamber, a take-up spool is rotatably disposed for winding the filmstrip. Back and front press springs are provided in a back side of the camera and in a side of a taking lens respectively, and fixed on a inner face of a wall of the film take-up chamber by press fitting. Thus, the back and front press springs strongly press the filmstrip on the take-up spool so as to wind the filmstrip around the take-up spool.
For example, a camera which is disclosed in U.S. Pat. No. 6,006,044 (a U.S. Patent corresponding to Japanese Patent Laid-open Publication No. H9-222648) or Japanese Patent Laid-open Publication No. H9-203943 has a main body in which a film take-up chamber is formed. To the main body, a fixed lens barrel constructing a lens assembly is attached, and the fixed lens barrel is formed with a part of the wall of the film take-up chamber. As the press spring is attached to the wall, the fixed lens barrel is supplied for the main body after the press spring is previously attached to the fixed lens barrel, which simplifies to constitute the camera. Further, as the part of the wall of the film take-up chamber is formed with the fixed lens barrel, the camera has a smaller size than that in which the whole wall of the film take-up chamber is formed with the main body.
However, in the camera disclosed in the publication No. H9-222648 and the like, as the press spring is attached to the fixed lens barrel, a reactive force of the press spring is effective to the lens barrel. For low cost and decrease of weight of the camera, the fixed lens barrel is made of plastics whose thickness is not so much. Therefore, the reactive force sometimes causes to deform the fixed lens barrel. If the fixed lens barrel is deformed, the lens assembly does not smoothly shift for- and backward, and the lens assembly can""t move along a designated optical axis of a taking lens.
An object of the present invention is to provide a camera in which a fixed lens barrel of a lens assembly is prevented from being deformed by a press spring.
A second object of the present invention is to provide a camera in which an imaginary central line of the lens assembly is always on and along a designated optical axis of a taking lens and a movable lens barrel smoothly slides.
In order to achieve the above objects, a camera of the present invention includes a lens assembly constructed of a movable lens barrel and a fixed lens barrel. The fixed lens barrel is fixed to a main body of the camera. In the main body, a film take-up chamber is integrally formed. A wall forming the film take-up chamber includes a front wall portion, a back wall portion. Between the front and back wall portions, a first opening is formed in a right side, and a second opening is formed in a left side. The fixed lens barrel is disposed such that a part thereof may cover the first opening, and partly construct the wall of the film take-up chamber. Further, the left wall portion is fixed to the main body with covering the second opening. First and second press springs are attached to the film take-up chamber for pressing a filmstrip onto a take-up spool which is rotatably disposed in the film take-up chamber.
The first and second press springs include clamp sections to nip the front wall portion and the back wall portion respectively. The front wall portion has at least one protrusion, and the clamp section has at least one hole to fit on the protrusion. The first and second press springs include rollers. The rollers are supported at respective free ends of the first and second press springs.
According to the invention, while the first press spring is attached to the film take-up chamber, the fixed lens barrel fixed to the main body is prevented from being deformed by a reactive force of the first press spring causes. Accordingly, the movable lens barrel can always slide smoothly, and the imaginary central line of the lens assembly is on and along the design optical axis of the lens.